EXT4-fs error (device loop5): ext4_mb_mark_diskspace_used:3887: comm syz.5.1576: Allocating blocks 497-513 which overlap fs metadata EXT4-fs (loop5): pa ffff888130271348: logic 128, phys. 385, len 8 EXT4-fs error (device loop5): ext4_mb_release_inode_pa:4904: group 0, free 0, pa_free 1 ================================================================== BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2601 [inline] BUG: KASAN: use-after-free in ext4_ext_remove_space+0x3496/0x40d0 fs/ext4/extents.c:2939 Read of size 4 at addr ffff888139465c18 by task syz.5.1576/5838 CPU: 0 PID: 5838 Comm: syz.5.1576 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_ext_rm_leaf fs/ext4/extents.c:2601 [inline] ext4_ext_remove_space+0x3496/0x40d0 fs/ext4/extents.c:2939 ext4_ext_truncate+0x1a3/0x250 fs/ext4/extents.c:4473 ext4_truncate+0x9be/0xfb0 fs/ext4/inode.c:4287 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline] ext4_write_begin+0xad4/0x12e0 fs/ext4/inode.c:1276 ext4_da_write_begin+0x321/0xbf0 fs/ext4/inode.c:2988 generic_perform_write+0x2b7/0x690 mm/filemap.c:3870 ext4_buffered_write_iter+0x4ed/0x670 fs/ext4/file.c:270 ext4_file_write_iter+0x440/0x1540 fs/ext4/file.c:-1 do_iter_readv_writev+0x478/0x5f0 fs/read_write.c:-1 do_iter_write+0x1fa/0x7b0 fs/read_write.c:855 vfs_writev+0x2df/0x570 fs/read_write.c:928 do_pwritev fs/read_write.c:1025 [inline] __do_sys_pwritev2 fs/read_write.c:1084 [inline] __se_sys_pwritev2+0x1af/0x2b0 fs/read_write.c:1075 __x64_sys_pwritev2+0xbf/0xd0 fs/read_write.c:1075 x64_sys_call+0x346/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:329 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f640fcb6799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f640e711028 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007f640ff2ffa0 RCX: 00007f640fcb6799 RDX: 0000000000000001 RSI: 0000200000000100 RDI: 0000000000000007 RBP: 00007f640fd4cbd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000005405 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f640ff30038 R14: 00007f640ff2ffa0 R15: 00007ffce620bda8 The buggy address belongs to the page: page:ffffea0004e51940 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x139465 flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea0004e51988 ffffea0004e51908 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x100cca(GFP_HIGHUSER_MOVABLE), pid 5640, ts 264394533251, free_ts 264631803469 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2d3a/0x2dc0 mm/page_alloc.c:4485 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5808 __alloc_pages_node include/linux/gfp.h:595 [inline] alloc_pages_node include/linux/gfp.h:609 [inline] alloc_pages include/linux/gfp.h:622 [inline] shmem_alloc_page mm/shmem.c:1591 [inline] shmem_alloc_and_acct_page+0x4a2/0x8d0 mm/shmem.c:1616 shmem_getpage_gfp+0xfe5/0x2310 mm/shmem.c:1912 shmem_fault+0x196/0x520 mm/shmem.c:2124 __do_fault+0x264/0x2f0 mm/memory.c:4192 do_read_fault mm/memory.c:4556 [inline] do_fault mm/memory.c:4697 [inline] handle_pte_fault+0x187d/0x2710 mm/memory.c:4911 __handle_mm_fault mm/memory.c:-1 [inline] do_handle_mm_fault+0x1af9/0x1de0 mm/memory.c:5333 handle_mm_fault include/linux/mm.h:1847 [inline] faultin_page mm/gup.c:976 [inline] __get_user_pages+0x80e/0x10c0 mm/gup.c:1197 populate_vma_page_range mm/gup.c:1529 [inline] __mm_populate+0x324/0x470 mm/gup.c:1638 mm_populate include/linux/mm.h:2704 [inline] vm_mmap_pgoff+0x262/0x430 mm/util.c:560 ksys_mmap_pgoff+0xf6/0x1d0 mm/mmap.c:1647 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86 x64_sys_call+0x83/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:10 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_pcp_prepare mm/page_alloc.c:1544 [inline] free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534 free_unref_page_list+0x13a/0x9d0 mm/page_alloc.c:3671 release_pages+0x1006/0x1060 mm/swap.c:1015 __pagevec_release+0x71/0xe0 mm/swap.c:1035 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x595/0x1470 mm/shmem.c:969 shmem_truncate_range mm/shmem.c:1068 [inline] shmem_evict_inode+0x21a/0xa10 mm/shmem.c:1150 evict+0x4c9/0x8d0 fs/inode.c:650 iput_final fs/inode.c:1779 [inline] iput+0x635/0x7c0 fs/inode.c:1805 dentry_unlink_inode+0x32f/0x3e0 fs/dcache.c:380 __dentry_kill+0x44f/0x650 fs/dcache.c:586 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x47/0x90 fs/dcache.c:893 __fput+0x580/0x8b0 fs/file_table.c:319 ____fput+0x15/0x20 fs/file_table.c:339 task_work_run+0x127/0x190 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa9e/0x27e0 kernel/exit.c:889 Memory state around the buggy address: ffff888139465b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888139465b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888139465c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888139465c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888139465d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs (loop5): Delayed block allocation failed for inode 15 at logical offset 188 with max blocks 4 with error 117 EXT4-fs (loop5): This should not happen!! Data will be lost